Well, I do take huge offense to being called "selfish." Crossdressing, being transgendered, all of this part of life, I did not choose. I live it, it is psychologically important and necessary for me to express a feminine side, it is what it is. This, in itself, certainly not "selfish," any more than say preferring to drink coffee over tea.
Many CD's and TG's really and truly believe that marriage will "cure" them. Once I am married, I will no longer feel the need to express myself in these ways...
Many CD's figure it is simply not important enough to reveal, its just a hobby, not hurting anyone, no big deal... why tell something unnecessary to tell?
Many CD's simply get caught up in the "when." It is about fear, about how to go about it. These are powerful and deeply felt emotional thoughts. It is "hard" to admit or share something that often has been a deep buried secret for most of ones life.
None of the above things seem peculiarly selfish...
If you somehow have overridden all of the above, Know exactly what to say, when to say it, how to say it, and know in your heart that marriage will not "cure" you, and...
really believe that crossdressing, even being transgendered, IS something so life altering that it will effect every aspect of the rest of your life and that of your family, then by all means come clean directly.
But if there is some nagging doubt about how serious, how awful, how completely game changing for all involved having a feminine side to express is, then the question remains open whether to tell anyone or not. Selfish? I don't think so...